'\" et
.TH PTHREAD_SPIN_UNLOCK "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
pthread_spin_unlock
\(em unlock a spin lock object
.SH SYNOPSIS
.LP
.nf
#include <pthread.h>
.P
int pthread_spin_unlock(pthread_spinlock_t *\fIlock\fP);
.fi
.SH DESCRIPTION
The
\fIpthread_spin_unlock\fR()
function shall release the spin lock referenced by
.IR lock
which was locked via the
\fIpthread_spin_lock\fR()
or
\fIpthread_spin_trylock\fR()
functions.
.P
The results are undefined if the lock is not held by the
calling thread.
.P
If there are threads spinning on the lock when
\fIpthread_spin_unlock\fR()
is called, the lock becomes available and an unspecified spinning
thread shall acquire the lock.
.P
The results are undefined if this function is called with an
uninitialized thread spin lock.
.SH "RETURN VALUE"
Upon successful completion, the
\fIpthread_spin_unlock\fR()
function shall return zero; otherwise, an error number shall be
returned to indicate the error.
.SH ERRORS
This function shall not return an error code of
.BR [EINTR] .
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
If an implementation detects that the value specified by the
.IR lock
argument to
\fIpthread_spin_unlock\fR()
does not refer to an initialized spin lock object, it is recommended
that the function should fail and report an
.BR [EINVAL] 
error.
.P
If an implementation detects that the value specified by the
.IR lock
argument to
\fIpthread_spin_unlock\fR()
refers to a spin lock object for which the current thread does not
hold the lock, it is recommended that the function should fail
and report an
.BR [EPERM] 
error.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIpthread_spin_destroy\fR\^(\|)",
.IR "\fIpthread_spin_lock\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 4.12" ", " "Memory Synchronization",
.IR "\fB<pthread.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
